$2-27.$ The square plate is deformed into the shape shown by the dashed lines. If $DC$ has a normal strain $lo{n}_x=0\mathrm{.}004,DA$ has a normal strain $lo{n}_y=0\mathrm{.}005$ and at $D,{}_{xy}=0\mathrm{.}02$rad, determine the shear strain at point $E$ with respect to the $x^{\text{'}}$ and $y^{\text{'}}$ axes.

Please draw on the diagram where the angles are and give step by step instructions. I am confused on where the angle is for E$,$ thanks